There's a selection of upper/lower ball joints that I have seen with and without zerks (grease fittings).

Do ball joints last longer with or without a zerk and why?

I think ...

The zerks allow contimination of the grease and increase wear.

Without the zerks, the joints will wear out faster than if they had them (does that make sense?).

 

it depends.... lack of grease will also wear them out prematurely... its better to have them though, you can control contamination of the zerk by cleaning it, you cant control running out of grease in a non serviceable unit

 

You can clean out the contamination with the Zerk by flushing it out untill it's clean. Zerk all the way.

 

Well, I hate zerk fittings personally, but I would stick with them.

only reason I hate them is i have to deal with them at work, it slows me down way to much in the pit ( jiffy lube)

wade

 

Zerk.

Put a rubber cap over it if you are worried about contamination.

 

I prefer zerks if you are going to wheeling it.

The seal type will eventually get flushed out. With the zerk you dont have to worry about that. I believe thats why the 4x4 comes with zerks and the 2x4 does not. I could be wrong though.

 

I prefer zerk fittings everytime.

The problem is they are becoming extinct on new vehicles.

 

Ditto. I think they purposely omit the zerks so that they can sell parts later down the road. I just drill a hole and install my own zerk.